In conventional systems, a digital front end or image input device produces raw raster image data which is transmitted to the print engine. While this raster image contains all the information needed to print the page, some further analysis is often required for optimal functioning of the print engine.
For example, in a conventional system, as illustrated in FIG. 1, a digital front end or image input device 10 may receive image data from an image source. This image data may be non-raster image data if it is coming from a computing device, or this image data may be raster image data if coming from a raster input scanning device. As noted above, the digital front end or image input device 10 produces raw raster image data.
This raw raster image data may be further processed by an image processing device or subsystem 20 so as to prepare the data for consumption by a rendering device in a print engine 30, such as a raster output scanning device, a laser, in a xerographic print engine. The print engine 30 renders the image data onto a medium to produce a hard copy thereof.
A typical xerographic print engine would include, as noted above, a raster output scanning device; a development subsystem; a transfer subsystem; a cleaning and re-charge subsystem; a fusing subsystem; and/or finishing subsystem.
The operations of the print engine 30 are conventionally controlled by a print engine controller 40. The print engine controller 40 may receive information relative to the image being rendered; such as pixel counts, toner consumption, etc.; from the image processing device 20 or feedback information from the print engine 30. This information is used by the print engine controller 40 to generate control signals that control the various operations of the various subsystems within the print engine 30.
An example of using information received by the print engine controller to generate control signals that control the various operations of the various subsystems within the print engine is disclosed in U.S. Pat. No. 4,649,500. U.S. Pat. No. 4,649,500 discloses a method for collecting data on the amounts of inks to be fed wherein the data being collected is useful in adjusting the feed amounts of the inks in a printing machine. As disclosed, printed pictures can be economically obtained by either on-line or off-line adjusting the ink fountains of the printing machine in accordance with the ink amount data. The entire content of U.S. Pat. No. 4,649,500 is hereby incorporated by reference.
Another example of using information received by the print engine controller to generate control signals that control the various operations of the various subsystems within the print engine is disclosed in U.S. Pat. No. 5,749,023. U.S. Pat. No. 5,749,023 discloses a method of compensating for toner cohesivity within a repository in a developer system by recording toner consumption rate and toner dispense rate over a given time within the developer system. A controller responds to the toner consumption and dispense rates over the given time period to compute toner residence time in the repository and estimate a degree of toner cohesiveness. The entire content of U.S. Pat. No. 5,749,023 is hereby incorporated by reference.
A further common example is the use of pixel counting. Pixel counting is used to determine toner or ink consumption. This information may be used by print engine controller to generate control signals that control the various operations of the various subsystems within the print engine.
In all the examples described above, the information provided to the print engine controller is typically generated as the print engine is writing the image. In the case of a xerographic printer, the information provided to the print engine controller is typically generated as the raster output scanning device is consuming the raster image data.
The generation of such data at this point in the process is too late with respect to controlling some of the parameters of the subsystems of the print engine that require sufficient lead time to make the appropriate adjustments. Examples of engine adjustments that need sufficient lead times may be, but are not limited to, reducing the process speed of a developer housing in response to low coverage, or changing the fuser temperature based on anticipated coverage.
In another example, the controlling some of the parameters of the subsystems of the print engine that require information from multiple pages must be known in advance to make the appropriate adjustments. Examples of parameters that require information from multiple pages be known in advance to make the appropriate adjustments may be, but are not limited to, potential for reload, degree of separation overlap (toner pile height), etc. This information may also require sufficient time to compute, making it difficult to generate in real time if it is generated as the print engine is writing the image.
Therefore, it may be desirable to provide an interface that allows the digital front end or image input device to compute and transmit additional side channel information, useful for engine controls. Moreover, it may be desirable to compute this information from a “thumbnail” image that is commonly computed already for other reasons. In addition, it may be desirable to provide information along with the image that is related to, but not be limited to: potential for reload or other artifacts, coverage information (possibly adjusted for IO1 effects), pile height information, and blank separations.
Since this information is computed before the image is transmitted to the print engine, any engine adjustments that are slow (such as reducing the process speed of a developer housing in response to low coverage, or changing the fuser temperature) may be made based on multiple successive pages' information. The engine control software knows which order the plates are imaged, so it is best able to combine information across pages.
A method of controlling a print engine from analyzed image content information electronically analyzes, prior to a print engine beginning to print an image, associated image data to generate image content information; transmits the image content information to a print engine controller; and adjusts a parameter of the print engine based on the transmitted image content information.
A method of controlling a print engine from analyzed image content information electronically analyzes image data to generate geometry dependent image content information; transmits the image content information to a print engine controller; and adjusts a parameter of the print engine based on the transmitted image content information.
An image rendering system includes a digital front end to electronically analyze non-raster image data to generate image content information; a print engine, operatively connected to the digital front end, to render the non-raster image data; and a print engine controller, operatively connected to the digital front end and the print engine, to control various parameters of the print engine. The digital front end transmits the image content information to the print engine controller. The print engine controller adjusts a parameter of the print engine based on the transmitted image content information.